This paper insists on similarities between Heidegger’s presentation of Dasein’s authentic understanding of time in Being and Time (§§ 79-80) and Thomas Mann’s attempts to “narrate time itself” in The Magic Mountain. It shows that Thomas Mann’s temporal experiments can contribute to a phenomenology of temporality, not merely by “illustrating” philosophical theses, but also by achieving something that goes beyond any phenomenological consideration on time: the enactment of fundamental temporal experiences.